Laipe, alabara kan beere idiyele ti okun polypropylene, alabara jẹ olupese ti awọn okeere apapọ ipeja, ti a lo nigbagbogbo jẹ okun polyethylene, ṣugbọn okun polyethylene jẹ elege diẹ sii, rọrun lati ṣii lẹhin wiwun, ati anfani ti okun waya alapin ni pe monofilament ti okun jẹ inira, knotting ko rọrun lati isokuso.Ṣugbọn polypropylene wuwo ju polyethylene.Ni imọ-jinlẹ, agbekalẹ molikula ti propylene jẹ CH3CH2CH3, ati agbekalẹ molikula ti ethylene jẹ CH3CH3.Polypropylene ni atomọmu erogba ọkan diẹ sii ju polyethylene, nitorinaa iwọn ti okun polypropylene wuwo ju polyethylene.

Ilana ti polyethylene jẹ bi atẹle: +

—(CH2-CH2-CH2-CH2)n—-

Ilana ti polypropylene jẹ bi atẹle: +

— (CH2-CH (CH3)-CH2-CH (CH3)-CH2-CH (CH3)) n—-

O le rii lati inu eto pe polypropylene ni ẹwọn ẹka diẹ sii ju polyethylene.Lẹhin ṣiṣe okun, nitori ipa ti pq ẹka, okun ti polypropylene ni o ni agbara ti o lagbara ju polyethylene, ati pe ko rọrun lati rọ.Awọn iwuwo ti polypropylene jẹ 0.91 ati iwuwo ti polyethylene jẹ 0.93, nitorina polyethylene yẹ ki o wuwo.

Okun polyethylene jẹ irọrun diẹ sii, rọra ati rirọ ju polypropylene.